Other topics about Measurement Using E5053A and External Mixer
This section describes the frequency offset function and applicable setting values/measurement values.
This function offsets the frequency readouts when using an external downconverter or external mixers. All the frequency data and marker readouts are converted along with the equation below.
RF = N × LO -/+ IF
Where RF is the DUT frequency, N is the harmonic number, LO is the LO frequency of the external downconverter or the mixer used.
You can use this function to display the setting values and measurement results of the E5052B in terms of DUT frequencies (frequencies before down-conversion).
This function supports an offset not only when the internal local signal (LO) supplied to the internal mixer is at the lower frequency side of the DUT signal, but also when it is at the higher frequency side.
The frequency offset function is available when the device configuration is A or B in Device configuration using E5052B and E5053A, and when the device configuration is C with the external mixer enabled.
Setting items to use the frequency offset function are as follows.
On/off setting of the frequency offset function
Setting of the conversion mode
Setting of the frequency of the local signal (LO)
Setting of the harmonic
Settings of the frequency offset function are common to all measurement modes (phase-noise measurement mode, spectrum monitor measurement mode, frequency/power measurement mode, and transient measurement mode).You cannot make these settings for each measurement mode separately.
Turn on/off the frequency offset function.
System > Instrument Setup > Frequency Offset (User Downconv.) > Frequency Offset > ON | OFF
Set the conversion mode of the frequency offset function.
System > Instrument Setup > Frequency Offset (User Downconv.) > Conversion Mode > RF = n * LO + IF | RF = n * LO - IF
When you select RF = n × LO + IF, Upper Side Band (USB) mode is used, while selecting RF = n × LO - IF, Lower Side Band (LSB) mode is used.
For information on the frequency conversion equations, see Frequency Conversion Equations.
Set the LO frequency of a mixer or a downconverter used.
The LO frequency range is as follows:
10 M to 110 GHz for the USB conversion mode
500 M to 110 GHz for the LSB conversion mode
System > Instrument Setup > Frequency Offset (User Downconv.) > LO Frequency
The LO frequency is used for the equations as described Frequency Conversion Equations. When the conversion mode is USB, the setting range is 10 M - 330 GHz, and when the conversion mode is LSB, 500 M - 330 GHz.
Set the harmonic number of a mixer.
System > Instrument Setup > Frequency Offset (User Downconv.) > Harmonic #
The harmonic number is used for the conversion equations as described in Frequency Conversion Equations. The setting range is 1-34.
The frequency conversion equations are as follows.
When the conversion mode is USB. (RF > N × LO)
RF = N × LO + IF
When the conversion mode is LSB. (RF < N × LO)
RF = N × LO - IF
,where RF is the DUT frequency, LO is the LO frequency of a mixer or a downconverter used, IF is the IF frequency of the downconverted signal, and N is the harmonic number.
All the measurement setup parameters concerning frequency can be input as DUT frequency when frequency offset function is applied. The applicable frequency range is from 20 M to 117 GHz. There are some constraints on measurement setup parameters actually depending on the IF frequency of the downconverted signal being fed into the E5052B, and it is determined by the measurement range of the E5052B.
The listed below may be needed on considering the frequency setting when using the frequency offset function.
Setting common to all measurement modes
Setting of the target frequency of the auto frequency control function
Spectrum monitor measurement mode
Setting of Start, Stop, and Center frequencies
That the start and stop frequency may be limited by the actual IF signal being inputted to the E5052B. For example, the IF frequency is 10 MHz, the maximum span is limited up to 2 MHz, 10 percent of the IF frequency, not the RF frequency.
Transient measurement mode
Setting of the frequency range (wide band) or the maximum frequency
When the frequency offset function is on, the Wide Freq Range softkey is not available, and the Wide Freq Span softkey appears instead. Use the Wide Max Frequency softkey to set the maximum frequency.
Setting of the target frequency (narrow band)
Setting of the phase reference frequency (narrow band, phase transient measurement)
Setting of the video trigger frequency (wide band)
Setting of the video trigger frequency (narrow band)
The listed below are the measurement results that the frequency data is converted by the use of frequency offset function.
Phase-noise measurement mode
Frequency of the carrier signal
Frequency/power measurement mode
Measurement data array for frequency measurement (frequency data of all measurement points in analyzer mode)
Frequency measurement data in tester mode
Transient measurement mode
Measurement data array for frequency transient measurement (wide band)
Measurement data array for frequency transient measurement (narrow band)